Mechanical Engineering Master's Thesis Defense

Mark Stoffels will present his Master's Thesis Defense on Marine Hydrokinetic (MHK) Power

Marine Hydrokinetic (MHK) Power involves harnessing the power of moving water to create clean, renewable energy. The primary structure of MHK energy devices are most commonly constructed using epoxy glass composite materials. Epoxy glass composites absorb moisture when subjected to a humid environment; this moisture absorption leads to degradation of mechanical properties of the composite. The objective of this study is to characterize the effects of tensile stresses on the moisture diffusion parameters of epoxy glass laminates, and how these changes ultimately influence mechanical properties.

A model is proposed which relates externally applied tensile stresses to changes in absorption capacity as well as diffusion rate. The model postulates that changes seen in the diffusion process are the result of stress-dependent changes in the free volume of the epoxy resin. The free volume changes of the resin are calculated through laminate plate theory, which itself becomes a function of fiber angle as well as a host of elastic properties of the constituents. Consequently, according to the proposed model, changes in diffusion parameters are dependent upon the magnitude of applied stress, the loading angle, as well as elastic properties of the constituents.